Guests started arriving at around 1 p.m., an eyewitness tells Us Weekly, noting that event trucks had been by earlier in the day to deliver tables, chairs, and alcohol from Pete's Wine and Spirits. Among the first to arrive was Barrymore's pal and fellow Hollywood mom Reese Witherspoon, who dressed for the occasion in a flower-print frock and brought with her a present she'd picked up at Cameron Diaz's house.

In total, around 50 people showed up with flowers and presents for the second-time mom-to-be. They stayed all afternoon; according to the eyewitness, Witherspoon, 38 — a mom of three herself — left at around 4 p.m.

As previously reported, Barrymore and husband Will Kopelman are expecting their second daughter later this year. (The Big Miracle actress and her art consultant spouse are already parents to little Olive, 18 months.)

"I'm bigger this time than my first time," the 38-year-old star told Ellen DeGeneres in January. "My doctor the other day was like, 'Yeah, so I think maybe pull back a little bit. I was like, 'Really?'"